1. Field of the Invention
The present invention relates to an image forming apparatus, an image display method, and a storage medium, and more particularly to a preview function of an image forming apparatus.
2. Description of the Related Art
In recent years, with improvement of the capability of a display device, such as an operation panel, an image forming apparatus has come to be equipped with a function of previewing data accumulated in a hard disk (BOX) of the image forming apparatus or image data obtained by scanning a sheet original. As one of such preview functions, a technique has been proposed in which characters or graphics included in an image to be printed are displayed in the same sizes as those of the image to be formed on a sheet, so as to enable a user to check the image size before printing (see e.g. Japanese Patent Laid-Open Publication No. 2001-166763). In the following description, this preview function will be referred to as “real-size preview”. Since the real-size preview function enables a user to check the size of characters or graphics included in an image before printing of the image, it is possible to prevent occurrence of a printing error that characters or graphics are printed in unintended sizes.
The image forming apparatus is configured to be capable of accumulating data in various formats, such as document data and image data, in the BOX of the image forming apparatus. Document data in such a format includes information, such as data sheet size information (output sheet size information) as a reference of a document size and resolution information. Image data includes information, such as the number of pixels of an image, resolution, and data sheet size information, etc.
However, data in some format does not have information with reference to which a print size is determined, such as data sheet size information and resolution information. Such data includes image data, such as JPEG. Since such image data does not have data sheet size information or resolution information, it is impossible to determine a print size. For this reason, the image data cannot be displayed for real-size preview.
Further, in printing image data, a reference print size is determined by causing a user to select an output sheet size desired for printing. However, it is impossible to known whether or not an image to be printed has an intended size, before the image is printed.